Oral enzymatic detoxification system: Insights obtained from proteome analysis to understand its potential impact on aroma metabolization

The oral cavity is an entry path into the body, enabling the intake of nutrients but also leading to the ingestion of harmful substances. Thus, saliva and oral tissues contain enzyme systems that enable the early neutralization of xenobiotics as soon as they enter the body. Based on recently published oral proteomic data from several research groups, this review identifies and compiles the primary detoxification enzymes (also known as xenobiotic-metabolizing enzymes) present in saliva and the oral epithelium. The functions and the metabolic activity of these enzymes are presented. Then, the activity of these enzymes in saliva, which is an extracellular fluid, is discussed with regard to the…

Salivary redox status: a key parameter involved in the release and perception of sensory stimuli in human

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Physiological and oral parameters contribute prediction of retronasal aroma release in an elderly cohort.

International audience; Malnutrition is a serious problem in the elderly while understanding flavour perception could be a tool for controlling appetite or food choices. To increase our knowledge, we characterised the health and oral physiology (oral volume, swallowing tongue force, number of teeth and salivary flow rate, protein content and antioxidant capacity) of a cohort of 54 community-dwelling French elderly as well as their individual retronasal release of five aroma compounds (2-pentanone, 2-nonanone, 2,3-hexanedione, octanal and linalool) by proton-transfer-reaction mass spectrometry (PTR-MS). In general, large variability across participants was observed in both oral physiological…

Understanding the release and metabolism of aroma compounds using micro-volume saliva samples by ex vivo approaches

International audience; This study investigated the behaviour of key aroma compounds in the presence of human saliva (200 mu L) from different individuals (n = 3) submitted or not to centrifugation (whole vs clarified saliva). HS-GC results showed that human saliva strongly decreased the release of carbonyl compounds (aldehydes and ketones). This effect was dependent on i) the structure of the aroma compounds and ii) the saliva composition. Whole saliva exerted a higher effect than clarified saliva on aroma compounds. Moreover, this effect was individual-dependent and related to the total protein content and the total antioxidant capacity of saliva. HS-SPME and LLE-GC/MS analyses revealed t…

Effects of EGCg on the metabolisation of aroma compounds and its implication on retronasal aroma

Wine matrix composition affects temporal aroma release as measured by proton transfer reaction - time-of-flight - mass spectrometry

This work was funded by the Ministerio de Economia y Competitividad (AGL2012-04172-C02-01), and Consolider Ingenio 2010 (Fun-C-Food, CSD2007-063, Projects). Dr Carolina Munoz-Gonzalez thanks Consejo Superior de Investigaciones Cientificas for its research contract co-funded by the European Social Fund together with Regional Council for Burgundy and Fondo Europeo de Desarrollo Regional (European Union) for experiments undertaken in Dijon, France.

Influence of Prebiotic Fructans on Retronasal Aroma from Elderly Individuals

This study investigates for the first time the role of fructans with prebiotic effects (oligofructose and inulin) on retronasal aroma among elderly individuals. The impact of oligofructose (20% w/w) on retronasal aroma release was investigated using proton transfer reaction-mass spectrometry (PTR-MS) after 73 elderly individuals consumed aqueous solutions aromatized with five aroma compounds (pentan-2-one, nonan-2-one, hexan-2,3-dione, octanal and linalool). The influence of oligofructose and inulin (10% w/w) on the perceived intensity (n = 26) of two aroma descriptors (butter and floral) was also studied together with the possibility of a dumping effect on aroma evaluation due to the sweet…

Understanding the role of saliva in aroma release from wine by using static and dynamic headspace conditions.

The aim of this work was to determine the role of saliva in wine aroma release by using static and dynamic headspace conditions. In the latter conditions, two different sampling points (t = 0 and t = 10 min) corresponding with oral (25.5 °C) and postoral phases (36 °C) were monitored. Both methodologies were applied to reconstituted dearomatized white and red wines with different nonvolatile wine matrix compositions and a synthetic wine (without matrix effect). All of the wines had the same ethanol concentration and were spiked with a mixture of 45 aroma compounds covering a wide range of physicochemical characteristics at typical wine concentrations. Two types of saliva (human and artifici…

Does interindividual variability of saliva affect the release and metabolization of aroma compounds ex vivo? The particular case of elderly suffering or not from hyposalivation.

The aim of this work was to study the effects of interindividual variability of human elderly saliva on aroma release and metabolization by ex vivo approaches. Thirty individuals suffering or not from hyposalivation were selected from a panel formed by 110 elderly people (aged >65 years old) that were matched by age and sex. Then, their stimulated saliva samples were independently incubated in presence of three aroma compounds (ethyl hexanoate, octanal, 2-nonanone) to perform headspace-gas chromatography and liquid/liquid extraction-gas chromatography mass spectrometry analyses. These assays revealed that the extent of saliva effect on the release and metabolization of aroma compounds was h…

Application of an in vivo ptr-tof-ms approach to determine differences in wine aroma release among wines spiked with different types of oenological tannins

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Aroma release in the oral cavity after wine intake is influenced by wine matrix composition

The aim of this study has been to investigate if wine matrix composition might influence the interaction between odorants and oral mucosa in the oral cavity during a “wine intake-like” situation. Aroma released after exposing the oral cavity of three individuals to different wines (n = 12) previously spiked with six target aromas was followed by an -in vivo intra-oral SPME approach. Results showed a significant effect of wine matrix composition on the intra-oral aroma release of certain odorants. Among the wine matrix parameters, phenolic compounds showed the largest impact. This effect was dependent on their chemical structure. Some phenolic acids (e.g. hippuric, caffeic) were associated t…

Main effects of human saliva on flavour perception and the potential contribution to food consumption.

Part of: Nutrition Society Winter Meeting 2017; Whole saliva is a mixture composed by the secretions of the major and minor salivary glands and the crevicular fluid, bacteria, cells and food debris. Its properties (flow and composition) are highly intra- and inter-individually dependent and reflect the health status of individuals. Saliva plays a key role in the eating process and on the perception of flavour. Flavour corresponds to the combined effect of taste sensations, aromatics and chemical feeling factors evoked by food in the oral cavity. It is a key determinant of food consumption and intake. This review summarises the evidence about the role of saliva in flavour perception and its …

Corrigendum to "Understanding the release and metabolism of aroma compounds using micro-volume saliva samples by ex vivo approaches" [Food Chem. 240 (2018) 275-285].

Assessment wine aroma persistence by using an in vivo PTR-ToF-MS approach and its relationship with salivary parameters

To better understand wine aroma persistence, the nasal cavity of nine volunteers was monitored by Proton Transfer Reaction-Time of Flight-Mass Spectrometry (PTR-ToF-MS) after they rinsed their mouths with three rosé wines (one control and the same wine supplemented with two tannin extracts) during four minutes. Wines were aromatised with a mixture of five target aroma compounds. Results showed that wine aroma persistence was highly compound-dependent: while esters disappeared very fast, other compounds such as linalool remained in the oral cavity for longer times after wine expectoration. A low effect of tannins (at 50 mg/L) on nasal cavity parameters was observed, with the exception for th…

Molecular mechanisms of aroma persistence: From noncovalent interactions between aroma compounds and the oral mucosa to metabolization of aroma compounds by saliva and oral cells

International audience; The present study aims to reveal the molecular mechanisms underlying aroma persistence, as it plays a major role in food appreciation and quality. A multidisciplinary approach including ex vivo experiments using a novel model of oral mucosa and saliva as well as in vivo dynamic instrumental and sensory experiments was applied. Ex vivo results showed a reduction in aroma release between 7 and 86% in the presence of the thin layer of salivary proteins covering the oral mucosa (mucosal pellicle). This reduction was explained by hydrophobic interactions involving the mucosal pellicle and by the ability of oral cells and saliva to metabolize specific aroma compounds. The …